I just noticed that beginning around December 20,2017 that Lr created a new folder to put my auto backups in. It used to be that we could create our own folder and assign the backups to go there. So I now have them in two places which I can correct by moving my previous backups to the new folder. How come the option of choosing my own folder is now gone?

Well, every time the backup dialog displays you have the option to change the location. It's just that changing to the next time Lightroom exits will force the backup dialog to appear the next time you close Lightroom.